Welt turning mechanism for straight bar knitting machines



March 6, 1951 H. w. START ET AL WELT TURNING MECHANISM FOR STRAIGHT BARKNITTING MACHINES Filed Dec. 11, 1946 Patented Mar. 6, 1951 WELT TURNINGMECHANISM FOR STRAIGHT BAR KNITTING MA- CHINES Harry Wilfred Start,Carlton, andErnest Start, Wilford, England, assignors to William CottonLimited, Loughborough, Leicestershire, England Application December 11,1946, Serial No. "115,418 In Great Britain September 6, 1945 Section 1,Public Law 690, August a, 1946 Patent expires September 6,1965

7 Claims. 11

This invention relates to improvements in welt turning mechanism, forCottons patent and other straight bar knitting machines, of the kind inwhich welt hooks are mounted in a bar which is advanced towards theneedles to receive in the welt hooks loops or kinks of an initial weltcourse, and is subsequently again advanced for the return to theneedles, of the loops or kinks of the initial course, held by the welthooks, in in order to complete the welt. In one mechanism of this kindthe welt bar is moved up to the needles by slides, having abutmentsthereon which engage with the welt bar when the slides are moved onhorizontal bearers in the appropriate direction. The motion of the weltbar away from the needles durin the knitting of the first part of thewelt iseffected by auxiliary take-up mechanism until such time as the,welt wires can be inserted when the auxiliary tape-up is put out ofaction and the normal take-up mechanism, which is connected to the weltwires, is brought into action. When sufficient fabric has been knittedto .form the welt the loops of the first course taken by the welt hooksare returned to the needles. For this purpose the welt hooks are movedinto position over the needles and the latter may be raised up so as topass through the loops or alternatively the loops may be taken by thepicot points and restored by the points to the needles. In either casethe welt hooks have to be disengaged from the loops and for this purposethe welt hooks have been provided with a raised part thereon,immediately behind the hook shaped ends of the welt hooks so that whenthe welt hooks are advanced towards the needles after the loops havebeen taken by the pieot points or the needles, the bights of yarn on thewelt hooks are raised to a higher level than the hook shaped ends of thewelt hooks, to permit of the latter being withdrawn clear of the loops.To assist in the clearing of the loops from the welt hooks the picotpoints or needles are raised slightly as the welt hooks are withdrawn.The withdrawal of the welt hooks is eifected by the auxiliary take-upmechanism and as this is only arranged to apply the necessary tension tothe work .for normal knitting the additional load imposed on it inwithdrawing the welt hooks clear of the loops is more than therelatively light springs are capable of overcoming. In addition, theshape of the welt hooks used, as disclosed in British Patent No.559,434, requires a sharp withdrawal .motion, in order to give the loopsan upward impetus to throw them clear of the hooks as the latter arewithdrawn. Occasionally it is possible that one or more loops near theselvedge may fail to cast 01? the hooks, and when this occurs one end ofthe welt bar is retained .in its forward position near the needles,while the other end is drawn off by the normal take-up mechanism. Inthese circumstances, the bar becomes locked and damage to the needles asthey rise up from the knock over position is liable to result. A sharppositive retraction of the welt bar clear ofi the needles would bothprevent the bar becomin so locked and at the same time would break thisoccasional misplaced loop, so that no damage to the machine will arise.

The object of the present invention is to provide a quick withdrawalmotion to the welt hooks at the appropriate time so that they can bewithdrawn clear of the loops whilst the latter .are' raised above thetops of the hook shaped ends of the welt hooks.

The present invention provides welt-turning. mechanism of the kindspecified, having mechanism for advancing the welt-bar towards theneedles to take the initial welt course and to restore it, means otherthan said mechanism for drawing the welt bar away from the needlesduring the knitting of at least the initial part of the welt, and meansfor imparting a quick retraction to the welt bar to disengage the welthooks from the initial course after the latter has been returned to theneedles. Preferably, the advancing mechanism is constructed and arrangedto apply the quick retraction also. In order to permit of this, meansmay be provided for disconnecting the advancing and retracting mechanismfrom the welt bar during the knittins of the welt prior to the secondadvance of the welt bar.

The invention further provides welt turning mechanism of the kindspecified having mechanism for advancin the welt bar towards the needles.to take the initial welt course and to restore it and for efiecting arapid retraction of said'bar to disengage the hooks from the said courseon its restoration, means for disconnecting said mechanism from the weltbar when the hooks have taken said initial course, and means other thansaid mechanism for moving the welt bar away from the needles subsequentto said disconnection and during the knitting of at least a portion ofthe welt prior to the restoring advance by said mechanism.

In apreferred arrangement. the foregoing bar advancing and retractingmechanism incorporates bar-advancing means for advancing the bar towardsthe needles, which means is movable.

towards and away from the needles, a releasable coupling for connectingthe bar to said meansfor rapid retraction by the latter, and means forcausing said coupling to be disengaged during a movement of thebar-advancing means away from the needles immediately following thefirst advance thereof. In this case, the said advancing means maycomprise at least one abutment movable towards and away from the needleswhich abutment is arranged to engage the retractable bar and thereby toadvance it towards the needles but which is capable of retiring movementaway from the bar when the latter is forward and the coupling isdisengaged. The coupling may comprise at least one releasable catch forcoupling the welt bar to the abutment to retire with the latter, and arelatively-stationary catch-release device movable into and out ofoperative position.

The invention further provides welt-turning mechanism of the kindspecified, having mechanism for advancing the welt bar towards theneedles, means operating through a portion of said mechanism forimparting a rapid retraction to the welt bar to disengage the welt hookson the completion of the welt, and an auxiliary take-up for drawing thewelt bar away from the needles during the knitting of at least a portionof the welt.

In order that the nature of this invention may be more readilyunderstood, reference will now be made to the accompanying drawings inwhich:

Figure 1 is a sectional-elevation showing the welt hooks into a positionto replace the loops on the needles, when a sufiicient number of courseshave been knitted to form the welt.

Figure 2 is an enlarged detail of part of Figure 1.

Figure 3 is a plan view of Fig. 2.

Figure 4 shows the head of one of the welt hooks.

In the drawing only part of the mechanism at one end of a needle bar isshown but it is to be understood that such mechanism is suitably coupledto the other end of each needle bar and the two mechanisms operate inunison. The welt hook bar I is mounted so that it can slide on a bracket2 towards and away from the needles 3 and is moved up to the needles totake loops of the first course drawn on the needles in the welt hooks Iaand again to restore the loops taken by the welt hooks to the needles tocomplete the formation of the welt, by a slide 4 which is oper ated atthe appropriate time by a cam 5 on the main shaft 6 of the machineengaging with a truck I on a pivoted arm 8 which is connected by rack 9and pinion ID to a rack II fixed to the slide 4. The truck I on the arm8 is held in engagement with the cam by a spring I2. The slide 4 isformed with an abutment 5 which engages with the welt hook bar I andmoves it towards the needles 3 when the slide 4 is moved in theappropriate direction. The slide 4 is operated to move the welt hooks Iinto position to receive the loops of the first course drawn on theneedles and is then withdrawn to an inoperative position. During theknitting of at least a portion of the welt the welt hooks Ia arewithdrawn from the needles 3 by the auxiliary take-up mechanism I3provided for this purpose. When sufiicient fabric has been knitted toform the welt the loops on the welt hooks are restored to the needlestocomplete the welt. For this purpose the welt hooks Ia are moved intoposition over the needles 3 by the slide 4 and when the loops on thewelt hooks have been engaged by the needles or by the picot points (whenthe latter are used to assist in the return of the loops to the needles)the welt hooks Ia are moved further in between the needles to raise thebights or yarn on the welt hooks above their hook shaped ends. The welthooks are then withdrawn and in order to obtain a quick withdrawalaction to the welt hooks whilst the loops are raised, the welt hook barI is, during this motion, positively connected to the slide 4 so as tobe withdrawn with the latter by means of the spring I2 previouslydescribed. The needles 3 or picot points as the case may be, may beraised slightly at the moment the welt hooks are withdrawn to assist inholding the loops clear of the Welt hooks during the withdrawal motion.

In order to connect the welt hook bar I to the slide 4, a catch I4 isprovided on the latter to engage with the welt hook bar I. The catch I4is pivoted to the slide 4 and is arranged so that it automaticallyengages with the welt hook bar I when the abutment 5' on the slide is inengagement therewith. For this purpose, the catch I4 may be formed withan extension I5 having a roller I6 which rides on the upper cam edge ofan arm IT. This arm IT has a steeply inclined part I'Ia on its upperedge in such a position relative to the needles that as the welt bar Iapproaches them the rod or roller I5 rides up the incline I la causingthe catch I I to engage the welt bar. At the required time thereafterthe truck I rapidly descends the flank of the cam 5 under the action ofthe spring I 2 and the welt bar is thus withdrawn quickly by the catch Il. When the roller I6 reaches the incline again during the withdrawal ofthe welt bar, it rides down the incline and the catch is released. Itwill be understood that the catch I4 is only operative when the weltshooks Ia are being withdrawn at the completion of the welt and thatprovision must be made to hold it in an inoperative position when theslide 4 is operated at the commencement of the welt. To this end, thelower edge of arm I! engages with a cam I8 mounted on a shaft I 9 andthe shaft I 9 is angularly adjustable about its axis to move the cam I8into and out of its operative position. When the cam I8 is in itsoperative position the arm I1 is raised thereby into a position whereatthe roller I6 may be raised by the incline Ila and when the cam I8 is inits inoperative position the arm I? is lowered to a position whereat theincline I'Ia is out of the path of the rod or roller I6 and the catch Iis disengaged. Preferably the catch is biassed into this position by aspring Ida and the rod or roller I6 rides on the bracket 2. The cam I8may be mounted on the shaft I9 which carries the welt guides normallyprovided to engage with and hold the ends of the welt wires 20 duringthe production of the first part of the welt and until such time as thenormal take-up mechanism 2| is brought into action. Provision may bemade for automatically adjusting the shaft at the appropriate times toput the cam I8 into and out of action in well known manner from thepattern chain or control drum of the machine. Further: more, sinceduring the knitting of the welt it is necessary that the slide 4 shallnot be continuously reciprocated but shall remain in a re-. tractedposition until it is required to advance the welt bar I at thecompletion of the welt, any suitable mechanism is provided under the control of said chain, drum, or their equivalent for rendering theadvancing cam 5 inoperativa for example by shogging truck 1 or bydisengaging rack 9 from pinion Ii). We claim:

1. Welt turning mechanism including the combination, with means forsupporting a plurality of needles, and a stationary support; of a weltbar slidably mounted on the stationary support and having a plurality ofwelt hooks adapted to cooperate with the needles; advancing andretracting means for moving the welt bar on said stationary supporttoward the needles for receiving loops or kinks of an initial weltcourse in the welt hooks and to return the initial course to theneedles; auxiliary means for withdrawing the welt bar from said needlesduring the knitting of at least an initial part of the welt; and meansfor periodically imparting a quick re traction to said welt bar todisengage the welt hooks from the initial welt course when the latterhas been returned to the needles.

2. Welt turning mechanism including the combination, with means forsupporting a plurality of needles, and a stationary support; of a weltbar slidably mounted on the stationary support and having a plurality ofwelt hooks adapted to cooperate with the needles; advancing andretracting means for moving the welt bar on said stationary supporttoward the needles for receiving loops or kinks of an initial weltcourse in the welt hooks and to return the initial course to theneedles; auxiliary means forwithdrawing the welt bar from said needlesduring the knitting of at least an initial part of the welt; means fordisconnecting the advancing and retracting means from the welt bar whenthe welt hooks have received the loops or kinks of said initial weltcourse; and means for periodically imparting a quick retraction to saidwelt bar to disengage the welt hooks from the initial welt course whenthe latter has been returned to the needles.

3. Welt turning mechanism including the combination, with means forsupporting a plurality of needles, and a stationary support; of a weltbar slidably mounted on the stationary support and having a plurality ofwelt hooks adapted to cooperate with the needles; advancing andretracting means for moving the welt bar on said stationary supporttoward the needles for receiving loops or kinks of an initial weltcourse in the welt hooks and to return the initial course to theneedles, comprising a abutment movable toward and away from the needlesand capable of abutting the welt bar in retracted position of the latterto move the same toward said needles; a releasable coupling forconnecting said welt bar to said abutment for rapid retraction orwithdrawal by the latter; and means for releasing said coupling duringwithdrawal of said abutment away from said needles following initialadvancement of said welt bar toward said needles by said abutment inorder to allow the latter abutment to be withdrawn from said welt bar instationary advanced position of the latter.

4. Welt turning mechanism including the combination, with means forsupporting a plurality of needles, and a stationary support; of a weltbar slidably mounted on the stationary support and having a plurality ofwelt hooks adapted to cooperate with the needles; a movable abutmentdisposed in effective position to abut the welt bar and positively slidethe latter toward the needles for receiving loops or kinks of an initialwelt course in the welt hooks thereof; a catch lever pivoted on theabutment so as to be movable therewith and having a forward- I yextending hook or catch for engaging with said welt bar periodically towithdraw the latter away from said needles; means for moving saidabutment toward and away from said needles; and means for periodicallyengaging with another portion of said catch lever and thereby effectingthe periodical engagement of the hook thereof with, and disengagement ofsaid hook from, said welt bar in advanced position of the latter toallow said abutment to be withdrawn from said welt bar while the latterremains in the advanced position.

5. Welt turning mechanism including the combination, with means forsupporting a plurality of needles, and a stationary support; of a weltbar slidably mounted on the stationary support and having a plurality ofwelt hooks adapted to cooperate with the needles; a movable abutmentdisposed in effective position to abut the welt bar and positively slidethe latter toward the needles for receiving loops or kinks of an initialwelt course in the welt hooks thereof; a catch lever pivoted on theabutment so as to be movable therewith and having a forwardly extendinghook or catch for engaging with said welt bar periodically to withdrawthe latter away from said needles; a rotatable cam shaft carrying aneccentric cam; a rocking lever having a follower roller engaging uponthe cam, a movable rack connected to said rocking lever to be movedthereby when the lever is rocked by said cam; a pinio rotatably mountedon said stationary support and meshing with said rack; a second rackmeshing with said pinion and connected to said abutment for moving thelatter by means of said cam; and means for periodically engaging withanother portion of said catch lever and thereby effecting the periodicalengagement of the hook thereof with, and disengagement of said hookfrom, said welt bar in advanced position of the latter to allow saidabutment to be withdrawn from said welt bar while the latter remains inthe advanced position.

6. Welt turning mechanism including the combination, with means forsupporting a plurality of needles, and a stationary support; of a weltbar slidably mounted on the stationary support and having a plurality ofwelt hooks adapted to cooperate with the needles; a movable abutmentdisposed in eifective position to abut the welt bar and positively slidethe latter toward the needles for receiving loops or kinks of an initialwelt course in the welt hooks thereof; a catch lever pivoted on theabutment so as to be movable therewith and having a forwardly extendinghook or catch for engaging with said welt bar periodically to withdrawthe latter away from said needles; means for moving said abutment towardand away from said needles; a rearwardly extending cam follower portionon the catch lever; a cam supporting shaft carrying an adjustable cam;and a cam supporting arm pivotally mounted on said stationary support ina position to rest on the latter cam and having an upper camming portionfor slidably supporting the cam follower portion of said catch lever andthereby periodically engaging the hook thereof with and disconnectingsaid hook from said welt bar in predetermined position of the latter.

7. Welt turning mechanism including the combination, with means forsupporting a plurality of needles, and a stationary support; of a weltbar slidably mounted on the stationary support and having a plurality ofwelt hooks adapted to cooperate with the needles; a movable abutmentdisposed in effective position to abut the welt bar and positively slidethe latter toward the needles for receiving loops or kinks of an initialwelt course in the welt hooks thereof; a catch lever pivoted On theabutment so as to be movable therewith and having a forwardly extendinghook or catch for engaging with said welt bar periodically to withdrawthe latter away from said needles; means for moving said abutment towardand away from said needles; 3, rearwardly extending cam follower portionon the catch lever; a cam supporting shaft carrying an adjustable cam; acam supporting arm pivotally mounted on said stationary support in aposition to rest on the latter cam and. having an .upper camming portionfor slidably supporting the cam follower portion of said catch lever andthereby periodically engaging the hook thereof with and disconnectingsaid hook from said welt bar in predetermined position of the latter;and auxiliary means for periodically withdrawing said welt bar with itswelt hooks from said needles.

HARRY WILFRED START.

ERNEST START.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

